E-book reaches orbit

PORTLAND, Ore.  Chinese taikonauts orbiting the Earth last month took with them a five-inch electronic paper display made by Hanwang Technology Co.

The crew of the Shenzhou-7 orbital flight took notes, read books and listened to recordings on the e-paper display, called the Hanvon eBook, said Bangjiang Wang, general manager of Hanwang Technology (Beijing). The Hanvon N510 used an electrophoretic display from E-Ink Corp. (Cambridge, Mass.).

Based on E-Ink's technology, the notepad-size display measures 11-mm thick, weighs six ounces, provides 15 days of standby power. It can be read at any viewing angle using normal reflected light.

Electrophoretic displays work by trapping microcapsules of white and black pigment—electronic ink—inside a thin film, where they float in a transparent liquid. The black microcapsules are negatively charged while the white ones are positively charged.

By laminating the film onto a substrate that can apply an electrical charge, either black or white microcapsules are forced to the surface at specific pixel locations. Unlike a LCDs, which must refresh each pixel location every few milliseconds, electrophoretic displays save power by sending electrical signals only to pixels that need to be changed.

The Hanvon display stored text and images. A stylus was used to input text and drawings as well as to play back audio recordings. The monochrome display supports several text and audio formats.